ARM: Add an ARMv4 architecture version.

This is needed for the tegra124's bootblock and includes enough implementation
to support that use. No caching is supported, although there are function
prototypes and stub implementations to satisfy includes and linking.

Change-Id: Ib79dde8c30eda98b3e823cba2ff6115a610bb2e8
Signed-off-by: Gabe Black <gabeblack@google.com>
Reviewed-on: https://chromium-review.googlesource.com/171401
Reviewed-by: Gabe Black <gabeblack@chromium.org>
Tested-by: Gabe Black <gabeblack@chromium.org>
Commit-Queue: Gabe Black <gabeblack@chromium.org>
(cherry picked from commit 221dc76b3ce4c1d73851c432333e091e1c60f0cb)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6783
Tested-by: build bot (Jenkins)
Reviewed-by: Ronald G. Minnich <rminnich@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

1 files changed, 98 insertions, 0 deletions

diff --git a/src/arch/arm/armv4/bootblock.S b/src/arch/arm/armv4/bootblock.S
new file mode 100644
index 0000000000..5f7de13ee3
--- /dev/null
+++ b/src/arch/arm/armv4/bootblock.S
@@ -0,0 +1,98 @@
+/*
+ * Early initialization code for ARM architecture.
+ *
+ * This file is based off of the OMAP3530/ARM Cortex start.S file from Das
+ * U-Boot, which itself got the file from armboot.
+ *
+ * Copyright (c) 2004	Texas Instruments <r-woodruff2@ti.com>
+ * Copyright (c) 2001	Marius Gröger <mag@sysgo.de>
+ * Copyright (c) 2002	Alex Züpke <azu@sysgo.de>
+ * Copyright (c) 2002	Gary Jennejohn <garyj@denx.de>
+ * Copyright (c) 2003	Richard Woodruff <r-woodruff2@ti.com>
+ * Copyright (c) 2003	Kshitij <kshitij@ti.com>
+ * Copyright (c) 2006-2008 Syed Mohammed Khasim <x0khasim@ti.com>
+ * Copyright (c) 2013   The Chromium OS Authors
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; version 2 of
+ * the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+.section ".start", "a", %progbits
+.globl _start
+_start: b	reset
+	.balignl 16,0xdeadbeef
+
+_cbfs_master_header:
+	/* The CBFS master header is inserted by cbfstool at the first
+	 * aligned offset after the above anchor string is found.
+	 * Hence, we leave some space for it.
+	 */
+	.skip 128			@ Assumes 64-byte alignment
+
+reset:
+	/*
+	 * Set the cpu to System mode with IRQ and FIQ disabled. Prefetch/Data
+	 * aborts may happen early and crash before the abort handlers are
+	 * installed, but at least the problem will show up near the code that
+	 * causes it.
+	 */
+	msr	cpsr_cxf, #0xdf
+
+	/*
+	 * Initialize the stack to a known value. This is used to check for
+	 * stack overflow later in the boot process.
+	 */
+	ldr	r0, .Stack
+	ldr	r1, .Stack_size
+	sub	r0, r0, r1
+	ldr	r1, .Stack
+	ldr	r2, =0xdeadbeef
+init_stack_loop:
+	str	r2, [r0]
+	add	r0, #4
+	cmp	r0, r1
+	bne	init_stack_loop
+
+/* Set stackpointer in internal RAM to call board_init_f */
+call_bootblock:
+	ldr	sp, .Stack /* Set up stack pointer */
+	ldr	r0,=0x00000000
+	 /*
+	  * The current design of cpu_info places the
+	  * struct at the top of the stack. The number of
+	  * words pushed must be at least as large as that
+	  * struct.
+	  */
+	push	{r0-r2}
+	bic	sp, sp, #7 /* 8-byte alignment for ABI compliance */
+	/*
+	 * Use "bl" instead of "b" even though we do not intend to return.
+	 * "bl" gets compiled to "blx" if we're transitioning from ARM to
+	 * Thumb. However, "b" will not and GCC may attempt to create a
+	 * wrapper which is currently broken.
+	 */
+	bl	main
+
+/* we do it this way because it's a 32-bit constant and
+ * in some cases too far away to be loaded as just an offset
+ * from IP
+ */
+.align 2
+.Stack:
+	.word CONFIG_STACK_TOP
+.align 2
+/* create this size the same way we do in coreboot_ram.ld: top-bottom */
+.Stack_size:
+	.word CONFIG_STACK_TOP - CONFIG_STACK_BOTTOM